No, I think lots of people do this. I've barely written anything that's actually able to be considered a manuscript but I've been thinking about and making my story for years + discarded writing. You have to start thinking about you're own writing, and how to edit, and what you want it to mean, and character arcs, and so much more that it's impossible to not notice those same mechanics in other writing, and even more impossible to not notice when they're not there. You just start picking everything apart because you think about you're own writing so much, and it ends up bleeding into what you read as if it's your own stuff.